The restoration and preservation of hard surfaces generally utilizes the technology of the cleansing art which includes soaps and detergents; the solvent treating art; and coating or paint technology. In fact, to properly renew as well as protect surfaces, treatments often include application of various compositions which require tiem-consuming preparations, sequential treatments, and careful handling and application of the compositions. This is particularly the case where the surface to be treated is adjacent to another surface which does not require the treatment. Examples of such surfaces include tiling or paneling where only the adhesive joint surfaces between the pieces or panels require treatment. Such surfaces may be found in the household, as in furniture such as on table tops, flooring, and walls; and on outdoor surfaces, such as on boats; and in the point of bricks or other construction blocks.
The term adhesive, as used to describe the composition of such joint surfaces, generally refers to a substance capable of holding materials together by surface attachment, such as cementitious materials and polymeric resins including, for example, organic resins and silicone resins. The materials held together by the adhesive are termed adherends. The adhesive joint is also referred to as a grout, particularly when describing the joints between tile and other construction materials. Typical grouting compositions are described, for example, in U.S. Pat. No. 2,934,932 issued to Wagner and U.S. Pat. No. 3,706,696 issued to Bernett et al.
Examples of adherends which are attached to each other by an adhesive joint include structural clay products including brick, soaps, Slaughterhouse tile, glazed and unglazed clay block and non-Portland cement-containing structural products such as plastic, metal, fiberglass, glass plate, etc. Other adherends include glazed and unglazed wall tile, quarry tile, glazed and unglazed ceramic mosaics, and glazed floor brick. The adhesive joints may consist of, for example, Portland cement, mastic grout and epoxy materials.
The adhesive material used to form an adhesive joint generally is chosen for its strength and for its ability to form a strong bond to the surface of the adherend. The adhesive usually contains large quantities of filler materials which add bulk to the adhesive as well as improving its workability in applying it to the surface and increasing its strength. While the inculsion of fillers has these and other advantages, it also causes the adhesive jont to form a rough surface with many crevices, often rendering the joint surface porous to liquids and highly vulnerable to picking up diret and discoloration.
A grouting composition commonly employed in the ceramic tile industry is that of the Portland cement type. Such compositions suffer from several undesirable properties For example, the cement-type grouts are generally rough textured and porous thereby collecting dirt and other matter and allowing the transpiration of water. The grout surface is reactive and it readily discolors and stains thereby detracting from its original aesthetic or decorative appearance. The grouts are not readily avaliable in decorative colors to match or contrast with the ceramic tile. In addition, they often act as an environment for microorganisms. A well known example of such grouts is that found in bathroom tile installations.
While treatment of such joint surfaces with cleaning agents or solvents offers a temporary solution to the problem, because of the nature of these surfaces, they are quickly apt to become dirty and require often and repetitive treatments. Moreover, such cleaning agents offer no aid in preserving the compositons in the joints.
In the past , the renewal of grout joints entailed the removal of the grouting material by mechanical means, such as scratching and scraping, followed by re-installation of a similar material. This is expensive and time consuming and does not solve the basic problem of poor performance. The same problem will recur since the same type of grouting composition was re-installed.
On the other hand, coatings and paints which offer a protective coating for the joint surfaces require difficult and tedious applications to prevent the coating of the adjacent surfaces. Removal of such coating material from the adjacent surfaces often require delicate cleaning methods with noxious chemicals. As a result, devices for applying such coatings to very limited surface areas have been developed. These devices range from the very familiar caulking gun to more sophisticated devices like "Tileliner" manufactured by White Line, Inc., of Atlanta, Georgia. "Tileliner" has a special applicator which comprises a small vial filled with a liquid of the consistency of paint. A special rubber cap device with an applicator wheel is attached to the vial. The wheel is rolled along the joint, effectively covering the surface area of the joint in contact with the wheel. This technique still does not overcome the very tedious and timely application over large areas. Moreover, it is dependent upon the applicatior not clogging with the coating composition.
Additionally, the use of the applicator is also very limited by the size and shape of the joint to be coated. If the joint is narrower than the wheel width, the wheel does not touch the joint and the application is unsatisfactory. If the joint is wider than the wheel, a number of strokes with the applicator are required, resulting in a joint with an uneven appearance. If the joints are not straight, application is difficult. In all cases when the applicator comes to an intersection and crosses over a previously-applied area, it causes a raised area since it is thicker in this area than on either side of the intersection.
The coating composition used in the "Tileliner" as well as other known compositions are deficient in one or more respects. Many of these compositions cannot be applied over surfaces which are dirty or oily. In many cases the surfaces must first be extensively cleaned. As the joint surfaces are generally roughly textured and porous, many compositions do not obtain good bonds and adhesion with the substrate. Additionally, compositions have not heretofore existed which could provide an adhesive joint with acceptable water resistance, mildew proofing, and stain resistance. Many such compositions readily discolor and do not improve the aesthetic or decorative appearance of the adhesive joint. The aesthetic appearance not only includes color but also the texture of the coated surface.
For example, the composition used in the "Tileliner" when cured does not yield a glossy texture and does not resist stains such as permanent blue-black ink. Also, the coating will not adhere well to the substrate if the substrate is not meticulously clean and dry.
Another problem with such compositions is the difficulty in removing excess coating composition from adjacent surfaces. Removal requires use of special solvents. Not only are some of these solvents dangerous and odorous, but also remove some of the coating from the desired substrate.